1. Field of the Invention
This invention relates to a process for the preparation of bromoacetic acid and esters thereof.
2. Description of the Prior Art
Some of bromoacetic acid esters have been broadly used as non-medical bacteriocides which show remarkable antibacterial activities. A generally well-known synthetic method of bromoacetic acid esters is that acetic acid is reacted with bromine in the mixed solvent of acetic anhydride and pyridine and the resultant is esterified, as reported in Organic Synthesis, Collective Volume 3, p. 381 (1943), Paragraph of Synthesis of ethyl bromoacetate.
On the other hand, as synthetic methods of bromoacetic acid there have been known the reaction of chloroacetic acid and hydrogen bromide (Ber. 9, 561 (1876)), the method of bubbling gaseous hydrogen bromide into a solution of chloroacetic acid ester and hydrogen bromide (W. German Provisional Publication Specification No. 2,151,563 (1973)) and the method from chloroacetic acid in a similar way with said Specification No. 2,151,565 (U.S. Pat. No. 3,130,222 (1964. Also, the reaction of acetic acid and bromine in the mixed solvent of acetic acid anhydride and pyridine as described in the above Organic Synthesis has been known as a general method for preparing bromoacetic acid.
As represented by these prior publications, bromoacetic acid esters could be prepared by firstly reacting acetic acid or chloroacetic acid with a brominating agent to prepare bromoacetic acid, then isolating it, and subjecting the product to a conventional esterifying method, i.e., such as esterifying bromoacetic acid with an alcohol in the presence of a catalyst such as sulfuric acid.
However, such known methods are disadvantageous on practices in an industrial scale, because their procedures are comparatively laborious, and in addition their yields are not satisfactory and their reaction times are sometimes long.
It is an object of the invention to prepare bromoacetic acid as well as its esters, by a compact procedure and with high yields using raw materials of cheap prices.